Photocatalysis of low-concentration gaseous organic pollutants over electrospun iron-doped titanium dioxide nanofibers

In this study, iron-doped titania (Fe-TiO2) nanoparticles were prepared and then coupled to a polymer material as a support to synthesize Fe-TiO2 nanofibers for photocatalytic degradation of gaseous pollutants (benzene, toluene, ethyl benzene, and o-xylene (BTEX)) at environmental sub-ppm levels. The characteristics of as-prepared photocatalysts were determined by SEM, XRD, and FTIR analyses. Spectral analysis of the as-prepared photocatalysts revealed that they were closely associated with the characteristics of Fe ions for Fe-TiO2 nanofibers. The photocatalytic degradation efficiencies (PDEs) of BTEX determined via Fe-TiO2 nanofibers varied with the ratios of Fe to Ti, suggesting the presence of an optimal Fe-to-Ti ratio. In addition, the PDEs of BTEX determined via two Fe-TiO2 nanofibers with low Fe-to-Ti ratios (0.001 and 0.004) were higher than those obtained from the undoped Fe-TiO2 nanofibers, whereas those of the other two Fe Ti02 nanofibers with high Fe-to-Ti ratios (0.008 and 0.012) were lower. The average PDEs of BTEX decreased from 34 to 9%, 68 to 28%, 83 to 45%, and 90 to 55%, respectively, as the stream flow rates increased from 1 to 4 L min(-1). These values also decreased with increasing initial concentration (IC). Specifically, at the lowest IC of 0.1 ppm, the average PDEs of BTEX were 33, 68, 83, and 91%, respectively, while they were 5, 8, 12, and 23%, respectively, at the highest IC of 2.0 ppm. Similarly, the PDEs of BTEX decreased significantly as the RH increased. Overall, the electrospun Fe-TiO2 nanofibers could be used to effectively decompose low-concentration gaseous organic pollutants when operational conditions were optimized. (C) 2013 Elsevier Masson SAS. All rights reserved.